The invention relates to an electric cooking unit comprising an electric IR lamp supported in a housing. The housing is provided with a base wall and side walls arranged on said base wall, said side walls having apertures. The electric IR lamp comprises
a tubular lamp vessel sealed in a vacuum-tight manner and consisting of glass having an SiO.sub.2 content of at least 95% by weight, PA1 a tungsten filament in the lamp vessel having helical turns, and PA1 current supply conductors extending from the filament to the exterior of the lamp vessel. PA1 the turns of the tungsten filament directly engage the wall of the lamp vessel and PA1 the filament has during operation a temperature lying between approximately 1200.degree. C. and approximately 1500.degree. C.
The lamp vessel being arranged in the housing so that its ends project through the apertures in the side walls to the outside. The invention further relates to an electric cooking apparatus provided with such a cooking unit.
Such an electric cooking unit is known from EP No. 0,169,643 A1.
Such electric cooking units have one or more halogen infrared (IR) lamps, which during operation at design voltage consume a power in the range of approximately 450 to approximately 850 W. This power should be consumed with a comparatively small lamp length. As a result, the power consumption has a high value of approximately 20 to approximately 30 W/cm.sup.2 of radiating surface area. The filament has during operation a comparatively high temperature of approximately 1800.degree. C. This is in contrast with the temperature of conventional heating elements of, for example, chromium/nickel or chromium/nickel/iron/aluminium, which have an operating temperature of approximately 1000.degree. C. and are used in the open air. Such heating elements consume only a few watts per cm, however, and further have a comparatively short life of approximately 1000 hours.
The high operating temperature of the known IR lamps results in that the lamps emit a comparatively large quantity of light, i.e. approximately 5 to 6 lm/W. A lamp of, for example, 500 W therefore produces an unfavourably high luminous flux of approximately 2750 lm, which corresponds to the luminous flux of a GLS lamp of approximately 230 W. Known electric cooking units are therefore generally used under a hot plate of very dark color in order to absorb the light produced at least for the major part in said hot plate.